Dye images obtained by development-processing silver halide color photographic materials are generally produced from azomethine dyes or indoaniline dyes formed by the reaction of oxidation products of aromatic primary amine type developing agents with couplers. Such dye images are not always stable to light and heat. As a result, discoloration or change of color in the image areas, or increase in stain frequently happens and thus the image quality deteriorates. In particular, deterioration of cyan image and increase in yellow stain are serious problems of color photographic papers since it is usual for the photographic papers to be kept in albums or the like at private homes.
Various attempts have been made to improve image quality for the purpose of solving the above-described problems.
For instance, Japanese Patent Application (OPI) Nos. 11330/74 and 57223/75 disclose enclosing dye images by oxygen-intercepting layers made up of substances having low permeability to oxygen, and Japanese Patent Application (OPI) 85747/81 discloses providing a layer having oxygen permeability of 20 ml/m.sup.2.hr.atm or less on the support side of an dye image forming layer of a color photographic material. These attempts have had some effect upon prevention of yellow stain. However, they produce no effect whatsoever on cyan dye images and, to make the matter worse, cases occur in which they accelerate deterioration of cyan dye images. Also, the method in which a surface-protecting layer is designed so as to have a multilayer structure, as described in Japanese Patent Publication No. 8346/81, fails to bring about a sufficient effect.
On the other hand, various cyan couplers have been developed for the purpose of forming stable cyan dye images. Examples of such couplers include two equivalent orthoacylaminophenol type couplers described in U.S. Pat. Nos. 3,772,002 and 3,998,642; 2,5-diacylaminophenol type couplers described in U.S. Pat. Nos. 2,772,162, 2,895,826, 3,758,308, 4,146,396, 4,362,810, 4,299,914, 4,334,011 and 4,463,086, Japanese Patent Application (OPI) No. 31954/84, and so on; and carbostyryl type couplers described in U.S. Pat. No. 4,430,423, Japanese Patent Application (OPI) Nos. 104333/81 and 134635/83, and so on. Though many of those couplers can produce cyan dyes excellent in fastness to heat, some of them have inappropriate hue and most of them suffer deterioration on fastness to light. In addition, they have no effect whatsoever upon prevention of yellow stain. Such being the case, no cyan couplers have yet developed with sufficiently high image fastness.
In addition, various discoloration inhibitors also have been developed. Examples of which include hydroquinone derivatives described in U.S. Pat. Nos. 2,360,290, 2,418,613, 2,675,314, 2,701,197, 2,704,713, 2,728,659, 2,732,300, 2,735,765, 2,710,801 and 2,816,028, British Patent No. 1,363,921, Japanese Patent Application (OPI) No. 24141/83, and so on; gallic acid derivatives described in U.S. Pat. Nos. 3,457,079 and 3,069,262, and so on; p-alkoxyphenols described in U.S. Pat. Nos. 2,735,765, 3,689,909 and 3,764,337, and Japanese Patent Publication No. 6623/77; p-oxyphenol derivatives described in U.S. Pat. Nos. 3,432,300, 3,573,050, 3,574,627, 3,764,337 and 4,113,495, and Japanese Patent Application (OIP) Nos. 35633/77 and 147434/77; and bisphenols described in U.S. Pat. No. 3,700,455, and so on. However, these compounds are still insufficient in discoloration inhibiting effect.
On the other hand, various means for obtaining images excellent in fastness have been developed based on photographic processing. For instance, it is common knowledge that a stabilizing bath is employed as the final bath. The stabilizing bath contains generally a pH controlling agent, a surface active agent, an image-stabilizing agent like formaldehyde, a brightening agent and so on. However, it has no effect upon discoloration of cyan images, and in many cases, it can only produce a slight effect on prevention of yellow stain.
Further, U.S. Pat. No. 4,336,324 describes a multistage counter current processing including no washing step, and for the purpose of preventing photographic materials from having yellow stains due to that processing, a chelating agent has been jointly employed (see Japanese Patent Application (OPI) No. 58143/82) and a water soluble bismuth compound has been added (see Japanses Patent Application (OPI) No. 134636/83). However, the attempts are insufficient to effect the above-described purpose.
Furthermore, it is known that the processing with a stabilizing bath having a high iron salt concentration can prevent images from discoloring, as described in Japanese Patent Application (OPI) No. 14834/83. However, this processing also is insufficent in prevention of yellow stains, and it is therefore hard to say that such can ensure excellent image fastness.
As mentioned above, it was very difficult to attain stabilization of color images, particularly cyan dye image, and prevention of yellow stains simultaneously. This difficulty is thought to result from the contrariness of conditions under which images undergo deriorations, that is to say, cyan dye images are subject to deterioration in a reductive atmosphere, whereas yellow stains tend to be produced in an oxidative atmosphere.